1. Field of the Invention
This invention relates to a process for making functionalized substituted bisphenol compounds using ion exchange resins. More particularly, this invention relates to the preparation of functionalized substituted bisphenol compounds from functionalized ketones or aldehydes with substituted phenols using macroreticular ion exchange resins. In an especially preferred embodiment, this invention relates to the synthesis of an acid functionalized bis-xylenol compound from levulinic acid and 2,6-dimethylphenol using a macroreticular ion exchange resin as catalyst
2. Description of the Prior Art
Condensation reactions, for example, the conversion of various phenols and functionalized ketones into functionalized bis-phenols, have been accomplished with mineral acids. For example, U.S. Pat. No. 3,567,686 describes in general terms the condensation of phenol with keto acids or keto esters such as levulinic acid to prepare bis-phenol compounds of ##STR2## the structure: COOR wherein A is a radical selected from the group consisting of hydrogen, methyl, and phenyl and R is an alkyl group containing one to eighteen carbon atoms, wherein the ester is prepared by reaction of the desired alcohol with the corresponding bis-phenol acid. The esters were described as useful in the polycarbonate resins.
The condensation of mono-alkyl substituted phenols wherein the alkyl group contains at least eight carbon atoms and keto-acids has been described in U.S. Pat. No. 3,954,808. At column 4, beginning at line 37, it is stated that the alkyl-substituted phenol preferably has at least ortho-position unsubstituted on the phenol ring. Acids such as sulphuric acid, p-toluenesulphonic acid, or a mixture of hydrochloric acid and glacial acetic acid were described as catalysts for the condensation reaction. Lactone structures from further condensation of the phenolic hydroxyl groups with the carbonyl-substituted carboxylic acid are also described.
Japanese publication JP62070338 (Tabayashi, et al.) refers to the preparation of functionalized bisphenols from phenols and keto-carboxylic acids using acid catalysis.
Japanese publication JP61186346 (Itsuda, et al.) refers to the preparation of 4,4-bis(4-hydroxyphenyl)pentanoic acid from phenol and levulinic acid using mineral acid catalysis.
Condensation reactions for the production of bis-phenols using ion exchange resins is fairly old and can be found in U.S. Pat. Nos. 3,049,568, 3,049,569 and 3,153,001 (Apel, et al) and 3,221,061 (Grover), among other references. Generally, the bis-phenol described is bis-phenol, a basic building block for polycarbonate resins. The use of ion exchange catalysts for the preparation of bis-xylenols containing acid moieties is unknown.
Due to the costs and efforts associated with the conversion and subsequent purification of bis-xylenols containing acid moieties prepared using mineral acids to catalyze the condensation reactions, it is apparent that a need exists for improved methods for the preparation of these materials.